doc/variables.txt was missing the already-existing BUILDLOG
variable description, and ARCHES got added during multi-target
toplevel rewrite.  Other minor fixes come as appropriate.

Here we go with postprocessing priorities along the way
as ISO hybridization has to occur before implanting
final MD5 sum (which must happen earlier than e.g. some
external MD5SUM file generation).

Unfortunately proper dependencies aren't applicable here
(though I'd like to be proved wrong on this one).

Please note that this needs propagator > 20101130-alt9
for automatic mode to work (has also been worked around
in gfxboot case with design-bootloader-source-6.0-alt1).

Thanks rom_as@ for asking about the hybrid image status
and helping out with testing.

The idea is to check:
- the reachability of every target
  used to build the image in question;
- the availability of all the package lists
  and subsequently packages for that image;
- the lack of "dangling" intermediate targets,
  features, pkglists, hooks etc.

So far only the first step is implemented --
it's easy and somewhat helpful already for
  make CHECK=1 all

CLEAN is so useful and fiddling with .work chroots does
demand knowledge (hsh-shell is handy btw); so unless we
really get our hands dirty, let's spare ours preciouss
tmpfss.

- toplevel README received some long-needed refactoring
  + lowlevel detail moved, well, to lowlevel READMEs
- reflected more thoroughly that m-p is not about distros anymore
- dropped features.in/00example/README.en: it's already out-of-date
  a bit, and there's no perceived need in thorough English docs so far
- wiki article got split into parts and somewhat rewritten, links updated
- mv doc/{CodingStyle,style.txt}

This one regulates the build wrapper: if the value is non-empty
then nice(1) and ionice(1) will be attempted so that the build
behaves better in regard to other tasks running on the system.

A few doc/variables.txt updates along the way.

Unfortunately apt configuration is not straightforward at all
regarding being overridden: one can't just provide sources.list
but needs a corresponding apt.conf along with it, and that apt.conf
must disable the SysV-style snippet directories to avoid interesting
side effects of all the things getting overlaid.

So it's not surprising that torabora has asked for an example...
(thanks go to boyarsh@ since I asked him for an example long ago)

Implemented opportunistic alarm support as proposed by torabora;
the actual result depends on readline and/or terminal settings
(read up on "visual bell" vs "audible bell" in case it's wrong).

TODO: this ought to be shifted downstream when proper logging
framework is there.

This is quite a large-scale change since mkimage-profiles got used to
baking distributions over the last year, and virtual environments are
quite different, so e.g. image.in/Makefile had to be split in two with
the main part of it moved into features.in/iso/lib/.

Short overview:

- features.in/Makefile: lib/ support
  (supporting VE images requires dynamic modifications
  to image.in/Makefile before starting the build;
  the most natural way to achieve that seems to use
  features mechanism along with makefile include dir)

- packaging format related part moved into features.in/pack
  (should be better prepared for diversity either)
- features.in/iso renamed to features.in/build-distro
- features.in/ve  renamed to features.in/build-ve
  + NB: these could not be merged as e.g. features.in/build
    due to completely different script hooks

- lib/image.mk renamed to lib/build.mk
- image, config, log postprocessing moved downstream
- added a sort of a topping in the form of lib/sugar.mk
- assorted style fixups (like ifeq usage)

- clean.mk: reliability fix (the problem was observed by Oleg Ivanov
  and me too but finally it did get the attention quantum)

- reviewed, updated and extended docs
  + QUICKSTART: should be[come] a step-by-step guide
    (thanks Leo-sp50 for prodiving feedback)

install2 cleanups:

- functionally indifferent ones: particularly, install2/*/98system's
  "mkdir -p /image" was superfluous as it was done by that time already
  by sub.in/stage2/image-scripts.d/00stage1

- taken apart, prepared for tags: so far it's a mostly moot change
  since the installer cleanup scripts themselves are mostly the same as
  preceding 90cleanup was (with some additions corresponding to recent
  kernel development); it's still unclear what the mechanism for
  configuring the cleanups in effect will be, either directory/package
  regex lists or tagged scripts excluded from execution by yet another tag

fixes:

- image.in/Makefile: fix metadata related test; the actual test was
  assuming that stage1 kernel means installer, which is not the case
  since generic stage2 introduction; oh well

- 85cleanup-lowmem: a "_" too much was the culprit in destroying the
  needed translations along with those deemed superfluous; thanks go to
  Oleg Ivanov and Lenar Shakirov for finding the bug and proposing the
  fix altogether

additions:

- features.in/Makefile: reworked help target; it was rather inaccessible
  due to BUILDDIR normally undefined at the time of direct make
  invocation, and BUILDDIR is normally defined during normal builds
  anyways so let's try it this way.

- README++

daydreams:

- 01-genbasedir: we should drop bzip2 compressed pkglists some day
  but see genbasedir and apt-cdrom first, 90-pkg.sh (alterator-pkg)
  will fail miserably otherwise

Somewhat more uniform style and a few additional bits.

Rather minor fixups for things changed in the meanwhile and not
yet (re)documented properly; and a change for memtest feature
to require syslinux feature (the code's been changed to fit
the updated description, actually, and the change is purely
formal as no syslinux alternative is being used/planned so far).

distcfg.mk is nice for tracing the variable values' build-up,
but it's more useful to have a look at the final result sometimes.
So here it is, logged for each build and callable by hand.

Implementation based on m-p-d::profiles/scripts.d/03-syslinux
(but heavily modified for m-p of course)

- introduced generic stage2 subprofile (non-standalone)
- ported installer and rescue over to stage2/{install2,rescue}
- initial stage2/live (needs more work for sure)
- use make-initrd-propagator
- updated and somewhat extended doc/

NB: mind #26133, #26134

make CLEAN=1 will prune workdirs after packing their results,
so disk (or preferably tmpfs) usage will be lower

...including hasher note, thx m-p-d.

Renamed server-light.iso into server-ovz.iso to avoid brand dilution
and confusion (rider@'s server-light rather favours kvm, anyways).

Introduced KDEFAULT: a reliable default kernel chooser knob
since apt's regex ordering proved pretty unreliable.
Spelling things explicitly is better anyways.

SYSLINUX related features undergone pretty major rewrite
(that includes syslinux, hdt and memtest).

The problem to tackle was features.in/syslinux/generate.mk
assuming syslinux and pciids available in build *host* system;
this well might not be the case (or worse yet, those can be
just different).  So now we're a bit less elegant and a bit
more enterprise, stuffing things into chroot and working there.

Bunch of other fixes along the road, including ; to name a few:
- fixed memtest entry (overlooked while renaming SYSLINUX_ITEMS)
- new and shiny doc/CodingStyle
- gfxboot, stage1 target chain, hdt tweaks
- distro.mk rehashed
- README++
- TODO: dropped (integer overflow anyways)
  + actually moved off-tree to reduce commit spam
- s,\.config\.mk,distcfg.mk,g
- doc/profiles.mk.sample: sample ~/.mkimage/profiles.mk
- ...and assorted fixups/additions

Sorry for convoluted commit, this would have been pretty hard to
rework into some really readable shape (and you might be interested
in the original repo's history horrors then, anyways).

ToC:
- introduced doc/
- features.in/00example/
- READMEs and TODO for more
- code comments clarified

Some unrelated minor fixes bundled either.